Bronchus-associated lymphoid tissue lymphoma (BALToma) is a rare, low grade marginal zone lymphoma of the lung. Histologically, BALToma is characterized by the aggregation of extranodal, monoclonal B- lymphoid cells near the bronchial epithelium. The radiographic appearance of BALToma is variable, ranging from well circumscribed nodules, to dense consolidations with air bronchograms. We report two patients with histories of marginal zone lymphoma, who underwent resection of enlarging ground glass opacities (GGOs) found to be BALTomas.
Case 1A 69-year-old woman diagnosed with marginal zone lymphoma of the right lacrimal gland (CD 20+) was found to have multiple GGOs on her staging chest CT. The largest GGO was 2 cm in her left lower lobe. She was treated with radiation to the right eye and rituximab. Post treatment imaging demonstrated a stable left lower lobe GGO while the other GGOs decreased in size. Over the next 15 months the left lower lobe nodule increased in size (to 2.4cm) and density. She was referred for resection under the suspicion of bronchoalveolar carcinoma. As this lesion was deep within the parenchyma, a video-assisted thoracoscopic left lower lobectomy was performed. Histopathology confirmed a marginal zone B-cell lymphoma similar to the prior lacrimal gland lymphoma.Case 2A 55-year-old man with a history of a BALToma resected from his left upper lobe, was found after 5 years of serial imaging to have an enlarging 1.4cm GGO in the superior segment of his left lower lobe. The patient was referred for resection under the suspicion of bronchoalveolar carcinoma. He underwent a video-assisted thoracoscopic left lower lobe superior segmentectomy. Histopathology confirmed a marginal zone B-cell lymphoma (CD 20+, CD43+) similar to the prior left upper lobe BALToma.
The radiographic appearance of BALToma can be variable. In a study of 24 patients the predominant patterns (88% of patients) were described as masses or mass-like consolidations most often multiple and with air bronchograms. In a more recent study of 21 BALToma patients, the predominant CT scan pattern seen was consolidation with air bronchograms, followed by pulmonary nodules. In eight patients GGOs were found (2 solitary, 6 multiple), but not comment was made towards stability over time.
BALToma often poses a diagnostic dilemma due to its rarity, nonspecific presentation and diverse appearance on CT scan. It is important to consider BALToma in the differential of GGOs that are increasing in size, particularly in patients with a history of marginal zone lymphoma.
Kristina Bermas, No Financial Disclosure Information; No Product/Research Disclosure Information